Polyhipe resin

Another important consideration was the choice of resin. The use of Hmb was developed using resins composed of polydimethylacrylamide polymerized within the pores of a solid, macroporous support, either Pepsyn or polyhipe, both are exemplified below. The use of Hmb involves the switching of solvents from DMF to dichloromethane the resins mentioned have excellent swelling properties in both solvents. However, some commercial polystyrene supports have given poor results because of the need to switch solvents, which can cause problems due to resin shrinkage. 1 ... 

PolyHipe kieselguhr polyacrylamide gel in (Figures 2e and f) composite resin, beaded shape [62,63]... 

Figure 4 Electron Micrographs of Porous Structures of Composite Resins a) Polyhipe Manufactured by Inverse Polymerization b) 20% -Crosslinked Macroporous Polystyrene...

Synthesis of GRF (1-29) by Fmoc Continuous-Flow Strategy on Fmoc-Arg(Pmc)-polyhipe Polystyrene Resin ... 

Starting from Fmoc-Arg(Pmc)-polyhipe polystyrene-resin (1.7 g, 0.493 mmol), the weight increase of the resin was 1.6g. The crude peptide after cleavage 5neld 1.3g (93%, based on starting resin), showed two main peaks on RP-HPLC which were the GRF(l-29) peptide and the corresponding oxidized methionyl compound, as determined by H NMR. 

The polymerisation of polyacrylamide gels within the pores of Kieselguhrii or polyhipe-structures (PS-DVB-copolymer with 90% pore volume) 20 allows the synthesis of composite resins, which due to their low compressability are well suited for continous flow reactors. The Kieselguhr and polyhipe matrices serve thereby as skeletons whereas the polyacrylamide gels determine the chemical and swelling properties of the reactive matrix. 

The high mechanical stability of CLEAR resins allow their use in continous flow reactors as used in solid phase peptide synthesis. The retroacylcarrier protein sequence 74-65 was synthesised successfully in the batch mode on these resins and their properties were compared to resins like polystyrene, polyhipe, PEGA and TentaGel . 

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